Solid state light sources receive electrical power via power supplies, also referred to as drivers or driving circuits. A typical driving circuit is configured with an isolated power supply topology, and includes a filtering capacitor in parallel with the solid state light source(s) being powered. Depending on the input power source, a bridge rectifier may also be included in the topology. In off-line drivers, there is often requirement for safety isolation, which is commonly achieved with the use of transformers and optocouplers. This isolation layer effectively divides the driver circuitry into the primary (AC) side and the secondary (load) side. In case of a fault, in certain cases it may be necessary to shut down the primary side to reduce energy delivered to the secondary side.